Thin cement mantle and osteolysis with a precoated stem.

The radiographic and clinical results of 55 hips (52 patients) implanted with the Harris precoat hip prosthesis using second generation cementing technique were investigated in this study. All metal backed sockets were fixed with cement. The preoperative diagnoses were osteoarthritis secondary to dysplastic hips in 42 patients, primary osteoarthritis in six, rapidly destructive coxarthrosis in five, and osteonecrosis of the femoral head in two. The average age of patients at the time of surgery was 67 years. The average duration of followup was 8 years. The rates of aseptic loosening and osteolysis in the femoral side were 5.5% (three hips) and 12.7% (seven hips), respectively. Three sockets were loosened, and no osteolysis was detected in the acetabular side. The mantle of cement in the femur was graded using the criteria described by Mulroy et al. Twenty-seven of 55 (49%) hips had regions with a thin cement mantle less than 1 mm in thickness or a defect in the cement mantle. Osteolysis was detected in seven of the 27 (26%) hips. Locations of osteolysis were coincidental with those of thin cement mantle or defect with the exception of one hip. This study clearly shows that a thin cement mantle less than 1 mm in thickness and a defect in the cement mantle lead to osteolysis.